The present invention relates to methods for improving homing, retention and engraftment efficiency of transplanted cells.
Bone marrow transplantation (BMT) is a clinical procedure in which pluripotent hematopoietic cells obtained from the bone marrow are transplanted into a patient. BMT is the treatment of choice in several hematological disorders, including malignancies, Severe Combined Immune Deficiencies (SCIDs), congenitally or genetically determined hematopoietic abnormalities, anemia, aplastic anemia, leukemia and osteopetrosis.
Primitive or pluripotent hematopoietic stem cells usually reside in the bone marrow, although cord blood is another functional source of transplantable hematopoietic stem/progenitor cells (Gluckman, E., et al 1989 N. Engl. J. Med. 321:1174). All of these primitive hematopoietic cells may be identified by their surface CD34 antigen. Hematopoietic stem cells differentiate along one of two major pathways—either into lymphoid stem cells or myeloid stem cells. Both further differentiate into progenitor cells for each type of mature blood cell. These progenitor cells have lost the capacity for self-renewal and are committed to a given cell lineage. Thus, lymphoid stem cells differentiate into T or B progenitor and myeloid stem cells differentiate into progenitor cells for erythrocytes, neutrophils, eosinophils, basophils, monocytes, mast cells, and platelets.
Under steady state conditions, the majority of hematopoietic stem and progenitor cells reside in the bone marrow and only a few of these cells are detectable in peripheral blood. However, stem cells may be mobilized into the peripheral blood by treatment with myelosuppressive agents and/or certain hematopoietic growth factors. Studies have demonstrated that peripheral blood stem cells (PBSC) infused in a host exhibit enhanced potential for engraftment as compared to bone marrow-derived stem and progenitor cells. Thus, PBSC mobilized by chemotherapy, hematopoietic growth factors or a combination of these modalities are currently used in both autologous and non-autologous transplantation settings [Anderlini, P. and Korbling, M. (1997) Stem. Cells 15, 9-17]. In the case of non-autologous transplantation, the donors of stem cells are healthy individuals and the procedure for mobilization of stem cells into the blood stream has to be achieved with minimal discomfort. In this case, stem cells mobilization with hematopoietic growth factors is preferred to mobilization with antiblastic drugs (i.e. cyclophosphamide).
In addition to stem and progenitor cells, more differentiated cells can be used for transplantation, for treatment of diseases or conditions of specific organs or tissues characterized by cell dysfunction or cell death. For many such diseases current medical therapies or surgical procedures are either inadequate or nonexistent. Cellular therapy can replace or augment existing tissue to provide restorative therapy for these conditions. Exemplary cell types suitable for transplantation include: neural tissue derived cells, hepatocytes, myocytes, retinal cells, endocrine cells, melanocytes, keratinocytes, and chondrocytes. It has been shown in both animal models and in human studies that engraftment of transplanted cells can successfully reestablish tissue function. Thus, neurons can be transplanted, for example, for Parkinson's Disease and other neurodegenerative disease. Muscle cells, such as myoblasts, can be transplanted for, for example, treatment of ischemic cardiac myopathy. Islet cells can be transplanted to treat diabetes and/or other insulin- and glucagon-related disease or conditions. Differentiated blood cells, such as lymphocytes and dendritic cells, can also be transplanted, for example, for adoptive immunotherapy with NK cells.
However, studies have shown that the majority of transplanted cells, such as hepatocytes and neural cells, are cleared from the body following transplantation, and do not localize to target organs or tissues (De Roos et al Transplantation 1997; 63:513-18; Gagandeep et al, Gene Therapy 1999; 6:729-36). Efforts to improve homing, retention and engraftment of transplanted cells, such as treatment of hepatocytes with Con A before implantation (Ito et al, Muscle Nerve 1998; 21:291-7) have been only marginally effective. Thus, efforts have been directed to methods for pooling and storage of the freshly prepared cells (see, for example, U.S. Pat. Nos. 6,713,245 and 6,821,779 to Koopmans et al), in order to provide greater numbers of cells for transplantation.
Following transplantation, cells must migrate towards their target tissues. Chemoattractants, such as certain of the cytokines (CXCL1-CXCL16, and CCL1-CCL-27) aid in steering the cells towards their objective. Stromal cell-derived factor 1α (SDF-1α), also termed CXCL12, is a powerful chemoattractant of CD34+ cells, including hematopoietic stem cells and neural stem cells (Aiuti J. Exp. Med. 1997; 185:111-120) and is widely expressed in many tissues during development (McGrath Dev. Biol. 1999; 213:442-456) and adulthood (Imai Br. J. Haematol. 1999; 106:905-911). It also chemoattracts non-stem cells such as T lymphocytes. CXC chemokine receptor 4 (CXCR4) is the cognate receptor for SDF-1α and is expressed on stem cells. Recent studies have implicated SDF-1α/CXCR4 as a pathway that activates stem cells molecular programs and homing during injury (Jaime Imitola et al., Proc Natl Acad Sci USA. 2004 Dec. 28; 101(52): 18117-18122).
CD26/dipeptidylpeptidase IV (DPPIV) a membrane-bound extracellular peptidase that cleaves dipeptides such as SDF-1α from the N terminus of polypeptide chains after a proline or an alanine, is a non-lineage-specific antigen whose expression in hematopoietic and other cells is regulated by differentiation and activation. Proteolytic cleavage of chemokines has implications with respect to the ability of cells to be attracted and/or activated by chemokines (Baggiolini, M. 1998, Nature 392:565).
Several functional studies allude to the role CD26/DPPIV plays in migration and mobilization of T-cells and hematopoietic cells [Shioda et al. (1998) Proc. Natl. Acad. Sci. USA 95:6331]. Inhibition of endogenous CD26/DPPIV activity on CD34+ cells was shown to enhance the chemotactic response of these cells to SDF-1α (Christopherson K W 2nd, et al., Science. 2004 Aug. 13; 305(5686):1000-1003; Christopherson K W 2nd, J Immunol. 2002 Dec. 15; 169(12):7000-7008), while N-terminal-truncation of SDF-1α with DPPIV results in failure to induce the migration of CD34+ cord blood cells.
Nicotinamide (NA), the amide form of niacin (vitamin B3), is a base-exchange substrate and a potent inhibitor of NAD(+)-dependent enzymes endowed with mono- and poly-ADP-ribosyltransferase activities. ADP-ribosylation is implicated in the modification of a diverse array of biological processes (Corda D, Di Girolamo M. 2003; 22(9):1953-1958; Rankin P W, et al., J Biol Chem. 1989; 264:4312-4317; Banasik M. et al., J Biol Chem. 1992; 267:1569-1575; Ueda K, Hayaishi O, Annu Rev Biochem. 1985; 54:73-100; Smith S. Trends Biochem Sci. 2001; 26:174-179; Virág L, Szabó C. Pharm. Reviews. 2002; 54:375-429).
The endogenous ADP-ribosyl transferases responsible for mono- or poly-ADP-ribosylation reactions modify molecules involved in cell signaling, such as core histones (de la Cruz X, Lois S, et al., Bioessays. 2005; 27(2):164-75), the alpha-subunit of heterotrimeric GTP-binding (G) proteins, the small GTPase Rho, monomeric actin and elongation factor 2 (EF-2). These post-translational modifications lead to activation or inactivation of cell functions modulated by these proteins (Lupi R, et al., J Biol Chem. 2000; 275:9418-9424; Lupi R, et al. Biochem J. 2002:367:1-7; Yau L, et al., Eur. J. Biochem. 2003; 270:101-110).
U.S. Pat. Appl. 2004/0247574 teaches the use of CD26 inhibitors for improving engraftment efficiency of stem cell transplants by both improving stem cell homing to bone marrow and by increasing the number of mobilized donor stem cells. It does not teach down-regulation of CD26 surface expression but rather down regulation of CD26 catalytic activity. Specifically, U.S. Pat. Appl. 2004/0247574 does not teach the use of nicotinamide for down-regulating CD26 surface expression.
PCT Application IL03/00064 discloses the use of nicotinamide, and other inhibitors of CD38, for the inhibition of differentiation in ex-vivo expanding stem and progenitor cells. However, PCT IL03/00064 does not teach administration of nicotinamide for enhancing homing, retention and engraftment of cells, or administration of nicotinamide to stem and progenitor cells for short intervals of 3 days or less, administration of nicotinamide to non-stem and non-progenitor (i.e. committed) cell populations or the administration of nicotinamide without provision of conditions for cellular proliferation.
It is therefore the object of this invention to overcome the drawbacks described in the currently available treatments and provide compositions and methods for the enhancement of cell migration, retention and homing potential of transplanted cells.